smith



O. A. SMITH.

SELF- OPENING THREADING DIE.

APPLICATION FILED OCT. 30. 1917.

1,318,115. Patented Oct. 7,1919.

2 SHEETS-SHEET 1.

ATTORNEY v O. A. SMITH. -ssu OPENING THREADING DIE.

' mucmqu man om. a0. 1911. 1,318, l 15. Patented 0m. 7, 1919.

. 2 sums-snm 2.

UNITED STATES. PATENT OFFIQEQ OSCAR A. SMITH, 0F CLEVELAND, OHIO, ASSIGNOR TO NATIONAL-ACME COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

SELF-OPENING THREADING-DIE.

T 0 all 'tlhOflb it may concern Be it known that I, Oscar A. SMITH, a citizen of the United States, residing at Cleveland. in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Self-Opening Threading-Dies, of which the following is a specification. 1

This invention relates to self opening threading dies, the object of the invention being to provide an improved die of this class, in which the cutters or chasers Wlll not commence to open until the die has traveled on to the work the required depth or length.

In many self opening threading dies, of which I am aware, the chasers or cutters have been so arranged that they open gradually by reason of the gradual action of the cams controlling the chasers 0r cutters, so that there is a tendency to stretch or shave the thread during the opening"movement of the die. In the present improvement. however, the organization is such that the die will run on to the work the required depth without the cutters or chasers even starting to open until the required depth or length of work has been threaded, after which the cutters or chasers will be quicklyopened, thus avoiding as stated. any tendency to stretch or shave the thread during the opening of the die.. In other words, instead of the chasers or cutters gradually opening as the die travels toward the end of its out, whereby the last thread may be imperfectly made, in the present improvement. the chasers or cutters do not even commence to open until this last thread has been entirely or perfectly out like the preceding threads, so that the object of the present im'prove ment is the provision of a more eiiicient die,

yet havin all the advantages of self opening dies, in which the chasers or cutters together with the body of the die w1ll travel forward out of the shell without, however, the chasers opening or releasing themselves from the work until the last thread has been completely out, and which opening of the die is accomplished in the present improvement by the work itself after the last thread has been completely and properly cut.

In the drawings accompanying and forming a part of this specification.

F lgure 1 is a sectional view of this improved die taken on line 22 Fig. 2 and Specification of Letters Patent.

Application filed October 30, 1917.

Patented Oct. v, 19119. Serial No. 199,253.

looking in. the direction of the arrows, a piece of work IV being shown in position in the die; Fig. 2 is across sectional view taken on line 11 Fig. 1 and looking in the direction of the arrows; Fig. 3 is a cross sectional view taken on line 33 Fig. 1 and looking in the direction, of the arrows;Fig. 4 is a detail sectional view of the means for adJustmg the cam ring thereby to set the cutters for various depths of cuts; Fig. 5 is a sectional View taken on line 5-5 Fig. 2, and looking in the direction of the arrows, a piece of work WV being shown in position in the die; Fig. 6 is a. perspective view of the cutter or chaser adjusting cam ring; Fig. 7 is a perspective view of the die body or chaser carrier; and Fig. 8 is a. detail per spective view of a die cutter or chaser.

Similar characters of reference indicate corresponding parts in the several figures of the drawings.

In the preferred form thereof shown, this improved the comprises a die body 2 having a rearwardly extending hollow or cylindri cal shank portion 3. The body is provided with a plurality of radially extending guideways 4, shown herein as four in number. Each of these guideways is grooved or undercut at its rear to form laterally extending recesses 5, and in each of the guideways a die chaser or cutter 6 is mounted to slide. Each of these cutters is secured to a back plate or block 7 projecting beyond the side faces of the cutter and into the recesses 5 of the body. Each of these plates or blocks 7 is provided with a rearwardly extending pin 8 projecting into a suitable opening 9 in the die body midway of and in the rear of the recesses 5 and in each of these openings is located a spring 10 adapted to engage the pin 8 to shift the chaser or cutter outwardly from the axis of the body at the proper time thereby to open the die. The outer end of each cutter or chaser is curved or tapered circumferentially throughout the major portion thereof transversely or at right angles to the axis of the die, but this curved or tapered surface is straight axially of the die, that is. it runs parallel with the axis of the die. The die body at each side of the chasers is cutaway as at 11 to permit the proper rotary movement of the die body and chasers relatively to the cam ring 12, which is provided with four forwardly projecting cams or cam members 13, each of triangular form, the apex of each of which is adapted to engage the circun'iferential surface of a chaser at the proper time. The cam ring is also provided with a recess l-t to permit the insertion of the proper resetting handle into the die body as hereinafter described. The die cup or shell 15 is suitably bored as at 16 to receive the die body and cam ring and between the die body and cup wall 18 at the rear end of the bore 16 of the cup is located an axially bored driving plate or disk 17 encircling the shank 3 of the die' body and fastened to the inwardly projecting cup wall 12 of the shell by a screw 19. This inwardly projecting cup wall 18 of the shell terminates in an axial opening 20 also encircling the hollow shank of the body. The driving plate 17 is provided on its outer or forward face with a diametrically located recess 21 in the rear wall of which is located a pair of stations or pin openings 22, these pin openings being located a suitable distance apart and in the center of the recess 21. To one side of the recess 22 is located an elongated curved opening 23, in which a spring 24 is placed in position to engage a pin 25 projecting from the rear of the die body. Carried by and projecting from the rear of the die body is a pair of driving pins 22 adapted to enter the openings 22 of'the driving disk 17. When the die body, its shell and :am ring are properly assembled it will be observed that the cam ring encircles the die body in such position that the triangular cams will properly cooperate with the curved surfaces of the chasers, while the driving pins 22 of the die body will project into the openings 22 of the driving disk 17,

while the pin 25 hereinbefore referred to will project into the curved elongated slot 23 of the shell to engage the spring 24. A suitable adjusting post 26 projects through an elongated opening in the shell and is threaded into the periphery of the cam ring 12. The body also carries a plate 27 carrying a pair of adjusting screws 28 in a'linement with each other and each adapted to engage the post for adjusting the position of the cam ring in the usual manner. By unscrewing one and screwing up the other of the adjusting screws, the cam ring 12 is rotated circularly to the high or the low portion of the cam surfaces on the ends of the chasers,

thereby. giving the desired adjustment for larger or smaller cuts. When the parts are assembled in the foregoing manner, it will. be observed that the shank of the die body projects a certain distance into the rear axial bore of the shell or cup 15. To the end of the body shank is fastened by means of screws a spacing plate 29 and between this spacing plate and the inwardly projecting portion 18 of the die body are located suitable draw-back springs 30, each being located in an opening of the body.

Projecting from the rear of the die body is a pair of pins or studs 31 adapted to project into radial slots 32 of a float ring or plate 33 screwed to the main threading die shank 3+. In the rear of this float ring or plate is located a series of four openings 35 carrying helical springs 36, and surrounding the hub 37 of the main shank 3a is a back plate 38 screwed to the die body as at 39, and against which the springs 35 impinge. Secured to the front' of the die body is a chip guard 10. An elongated slot in the periphery of the shell or cup permits a handle $1 to be fastened in the periphery of the die body adjacent to the recess 14 of the cam ring, and by means of which the die body and its chasers may be rotated relatively to the cam ring to reset the chasers for a new piece of work.

WVhen the die is properly assembled and set, the cam faces of the chasers rest against the triangular extensions of the cam ring 12 and when the forward cutting movement of the die stops the body however will still move forward relatively to the shell or cup and the cam ring until the pins 22 release themselves from the drive stations or openings 22 of the driving disk or block 17,

whereupon the. die body and its chasers can then rotate with the work a sufficient distance to carry the body circularly relatively to the shell or cup and until the pins 22 are brought against the wall of the groove 21 eitherto the right or left according to whether a right or a left handed thread is being cut. This rotary movement of the body and chasers with the work thereby releases the chasers from the cams due to this circular movement of the die body whereupon when the chasers are released trom the cams the springs'lO will open the cutters or chasers in the usual manner.

lVhenthe die head is clear of the work it can be reset by means of the handle by rotating the die body in the opposite direction until the pins 22 are brought into register with and caused to reenter the stations or openings 22 of the driving plate or block, by means of the draw-back springs 30, which cause the pins 22 to reenter the openings 22. At this time the cam portions of the chasers will again be in engagement with the cam portions of the cam ring 12. i

In the operation of this improved die, when the die has cut the required length of thread, and the travel, of the slide or holding means to which the main die shank 34 is connected is stopped, the body of the die and the chasers carried thereby continue however, to travel forward or axially of the die relatively to the shell or cup and the cam ring. without however, the chasers opening or releasing themselves from the work until the pins 22 are disengaged from the openings 22 of the driving plate 17. When, how- I of the die chasers does not take place, so

ever, these pins are disengaged from their openings 22 as the cutters or chasers are still in engagement with the work, these cutters and the body will therefore be rotated with the work thereby to carry the cam portions of the chasers from under the triangular cams of the cam ring, the amount of this rotation of the chasers being limited by the side faces of the recess portion :21 of the driving plate or block 17. When the cam portions of the chasers are rotated away from the triangular cams of the cam' ring, the springs in the rear of the chasers immediately release them from the work.

From the foregoing it will thus be seen that when the forward cutting movement of the whole cutting die is stopped the the body and its chasers will however, continue to travel forward relatively to the shell and relatively to the cam ring, which is of course held against forward movement without the chasers releasing themselves from the work until the pins 22 are drawn out of the openings 22, whereupon the rotation of the'work acts to rotate the die bodyand chasers relatively to the cam ring thereby to release the cam portions of the chasers from the cam ring and permit the same to open only after the last thread has been completely out, so that as hereinbefore stated, until the last thread has been completely out, the opening that in the presentiimprovement the gradual opening of the chasers prior to the complete cutting of the last thread is prevented.

From the foregoing it will be observed that the adjustment of'the chasers or cutters is obtained by adjusting the cam ring relatively to the cam surfaces of the chasers and that these same cam surfaces on the chasers are also utilized for closing the chasers and that the triangular formation of the cams of the cam ring enable the desired adjustment of the chasers to be obtained to make the required depth of cut. It will also be observed that the forward travel of the die body does notaifect the position of the chasers relatively to the triangular portions of the cam ring and therefore does not re lease the chasers from the work, and that such release does not take place until the die body has traveled sufiiciently forward to disengage the pins or studs 22 from. the driving plate or block 16. When this has occurred, however, the rotation of the work rotates the die body and thus releases the chasers from the cam ring. and-permits them to open, so thatt-he cutters cannot open until the last thread has been completely and properly out.

It will be understood that the various de? tails may be more or less changed without departing from the spirit or scope of the claims.

The spring 24 here-inbefore referred to assists the die in tripping, particularly on fine threads. In other words. where the thread is of very fine pitch there might not be suffioient pull to rotate the body and chasers to open the head, and this spring is designed to insure this proper rotation.

I claim as my invention:

1. A self-opening threading die comprising a shell, a body movable axially of and rotatable relatively to said shell after the forward movement of the die has stopped thereby to release the cutting means from the work, radially movable cutting means carried by said body having their outermost or top surfaces curved or tapered circumferentially in opposite directions and substantially equally from the apex thereof and straight axially of the body, a rotatably adjustable but normally non-movable cam ring carried within the shell and cooperating with and rotatably adjustable relatively to the curved top surfaces of the cutting means whereby such curved sur- I faces are utilized both to adjust the cutting means to the depth of the cut and also to close and release said cutting means, drawthe reverse direction, and driving means carried by the body and shell and automatically operative for locking the body tothe shell and releasable on the axial forward movement of the body relatively to the shell and the cam ring thereby to permit such body to rotate relatively to the shell and the cam ring.

2. A self-opening threading die comprising a shell, a body movable axially of and rotatable relatively to said shell after the forward movement of the die has stopped thereby to release the cutting means from the work, radially movable cutting means carried by said body having their outermost or top surfaces curved or tapered circumferentially in opposite directions and substantially equally from the apex thereof'and straight axially of the body, a rotatably adjustable but normally non-movable cam ring carried within the shell and cooperating with and rotatably adjustable relatively to the curved top surfaces ofthe cutting means whereby such curved surfaces are utilized both to adjust the cutting means to the depth of the cut and also to close and release said cutting means, drawback means for returning the body to its normal position on rotating said body in the reverse direction, and driving means carried by the body and shell and automatically operative for locking the body to the shell and releasable on the axial forward movement of the body relatively to the shell and the cam ring thereby to permit such body to rotate relatively to the shell and the cam ring, said cam ring having a plurality of forwardly projecting independent triangularly formed cams.

3. A self-opening threading die comprising a shell, a body movable axially of and rotatable relatively to said shell after the forward movement of the die has stopped thereby to release the chasers fromthe work, radially movable chasers carried by said body, each having its outermost or top sur face curved or tapered circumferentially in opposite directions substantially equally from the apex thereof and straight axially of the body, a rotatably adjustable but normally non-movable cam ring carried within the shell and cooperating with and rotatably adjustable relatively to the curved top surfaces of the chasers whereby such curved surfaces are utilized both to adjust the chasers depthwise of the cut and also to close and release said chasers, drawback means for returning the body to its normal position on rotating said body in the reverse direction, and driving means carried by the body and the shell and automatically operative for locking the body to the shell, the

axial movement of the body relatively to the shell effecting a severance of the driving means thereby to permit the rotary movement of the body, said driving means comprising one or more openings and one or more driving pins cooperating therewith, the driving pins and openings being carried one by the body and the other by the shell.

4:. A self opening threading die comprising a shell, a chaser carrying body movable axially and rotatable after the forward movement of the die has stopped thereby to release the chasers from the work, radially movable chasers carried by said body, each having its outermost or top surface curved or tapered circumferentially and straight axially of the body, normally non-movable camming means carried by the shell and cooperating with the chasers, drawback means for returning the body to its normal position on.r"otating said body in the reverse direction, driving means carried by the body and the shell, the axial movement of the body relatively to the shell effecting a severance of the driving means thereb to permit the rotary movement of the b0 y, said driving means comprising one or more openings and one or more driving pins cooperating therewith, the driving pins and openings being carried one by the body and the other by the shell, and means for limiting the rotary movement of the driving pins and thereby the body when the pin or pins are withdrawn from their opening or openings and comprising a recessed portion in which each of said openings is located midway thereof and which recess is of greater diameter than a driving pin.

5, A selPopening threading die comprising a shell, a chaser carrying body movable axially and rotatable after the 'forward movement of the die has stopped thereby torelease the chasers from the work, radially movable chasers carried by said body, each having its outermost or top surface curved or tapered circumferentially and straight axially of the body, normally non-movable camming means carried by the shell and cooperating with the chasers, drawback means for returning the body to its normal position on rotating said body in the reverse direction, driving means carried by the body and shell. and comprising one or more openings carried by a rear wall of the shell and one or more driving pins carried at the rear of the body, and means for limiting the rotary movement of the driving pins and thereby the body when the pin or pins are withdrawn from their opening or openings and comprising a recessed portion in the rear wall of the shell in which each of said openings is located midway thereof and which recess is of greater diameter than a driving pm.

6. A self opening threading die comprising a shell, a body axially movable and rotatable relatively to said shell, chasers carried by said body, driving means located between the body and shell and comprising one or more openings and one or more driving pins cooperating therewith, the driving pins and openings being carried one by the body and the other by the shell, the part carrying the opening having a recess of greater width than a pin and midway of which recess the opening is located, the walls of said recess forming means for limiting the rotary movement of the driving pins and thereby the body when the pin or pins are Withdrawn from their opening or openings, means for returning the pin or pins into their opening or openings, and camming means carried by the shell and cooperating with the chasers, the body and chasers having an axial movement relatively to the shell independently of the forward movement of the shell thereby to effect a severance of the driving means between the shell and the body to permit the body and chasers to rotate with the work and release the chasers from the camming means and the work.

7. A self opening threading die comprising a shell, a body axially movable and r0- tatable relatively to said shell, chasers carried by said body, driving means located between the body and shell and comprising one or more openings carried by a rear Wall of the shell and one or more driving pins carried at the rear of the body, each of said openings being located in a recess of the shell having greater Width than a pin and midway of which recess its opening is located, the Walls of said recess forming means for limiting the rotary, movement 0t the driving pins and thereby the body when means and the work.

8. A self opening threading die comprising a shell, a chaser carrying body movable axially and rotatable after the forward movement of the die has stopped thereby to release the chasers from the work, radially movable chasers'carried by said body, each, having its outermost or top surface curved or tapered circumferentially and straight axially of the body, normally non-movable camming means carried by the shell and cooperating with the chasers, drawback means for returning the bodyvto its normal. position on rotating said body in the reverse direction, said ca'm'ming means comprising a cam ring having a plurality of forwardly pro- 30 'cams, and means for limiting the rotary jecting independent triangularly formed movement of'the drivingjpins and thereby the body when the pin or pins are withdrawn from their opening or openings and comprising a recessed portion in which each of said openings is located midway thereof and which recess is of greater diameter than a driving pin.

9. A self opening threading die comprising a shell, a body rotatable and also axially movable relatively thereto, chasers carried by said body, a cam ring carried by the shell and having a plurality of forwardly projecting independent triangularly formed cams cooperating with the chasers, the body and chasers having a. forward traveling movement relatively to and independently of the shell without releasing the chasers from the cam ring and also having a rotary movement independently of the shell to release the chasers from the cam ring.

10. A self opening threading die'comprising a. shank, a shell having a resilient connection with the shank, a body within the shell and having a resilient connection therewith for rotary and axial movements relatively thereto, severable driving means between the body and the shell chasers car-v ried by the body, and normally non-movable camming means carried by the shell and cooperating with the chasers, the independent axial movement of the body being effective to sever the driving means without releasing the chasers from the camming means and the independent rotary movement of the body relatively to the shell being eifective to release the chasers from the camming means and the work.

11. A self opening threading die comprising a shank, a shell having a resilient connection with the shank, a body within the shell and having a resilient connection therewith for rotary and axial movement relatively thereto, severable driving means between the body and the shell,chasers carried by the body, and normally non-movable camming means carried by the shell and cooperating with the chasers, the independent axial movement of the body being effective to sever the driving means without releasing the chasers from the cannning means and the independent rotary movement of the body relatively to the shell being elfeo tive to release the chasers from the camming means and the work, each of said chasers having its outermost or top surface curved or tapered circumferentially and straightaxially of the body, said non-movable camming means comprising a cam ring having a plurality of forwardly projecting independent triangularly formed cams.

12. Aself opening threading die comprising a shank, a shell having a. resilient connection with the shank, a body within the shell and having a resilient connection therewith for rotary and axial movements relatively thereto, severable driving means between the body and the shell, chasers carried by the body, normally nonmovable c amming means carried by the shell and cooperating with the chasers, the independent axial movement of the body being effective to sever the driving means without releasing the chasers from the camming means and the independent rotary movement of the body relatively to the shell being eflective to release the chasers from the camming.

means and the work, each of said chasershaving its outermost or top surface curved or tapered circumferentially and straight axially of the body, said non-movable camming means comprising a cam ring having a plurality offorwardly projecting independent triangularly formed cams, the severable driving means between thebody and and comprising a recessed portion in which,

each of said openingsislocated midway thereof and which recess is of greater diameter than a driving pin.

13. A threading (lie comprising a body having a plurality of radial slots, each terminating in a rearwardly and laterally extending recess, each recess having at its rear a groove, chasers carried in said slots and each having a laterally extending plate secured thereto and sliding within said recess, each of said plates having a rearwardly extending pin located in said groove, a spring within said groove engaging said pin, each of said chasers having its outermost or top surface curved or tapered circumferentially and straight axially of the body, and a non-movable camming means for closin said chasers.

14. A threading die comprising a body having a plurality of radial slots, each terminating in a. rearwardly and laterally extending recess, each recess having at its rear agroove, chasers carried in said slots and each having a laterally extending plate secured thereto and sliding within said recess, each of said plates having a. rearwardly extending pin located in said groove, a spring within said groove engaging said pin, each of said chasers having its outermost or top surface curved or tapered circumferentially and straight axially of the body, anda non-momble camming means for closing said chasers, said camming means comprising a cam ring having a plurality of forwardly projecting independent triangularly formed cams.

15. A threading die comprising a body having a plurality of radial openings, a plurality of chasers located therein, each of said chasers having acam surface curved or tapered circumferentially and straight axially of the body, and camming means cooperating with said cam surfaces and effec tive to adjust the chasers relatively to the work, the chasers and body having an axial movement relatively to the camming means without releasing the chasers from the work and also a rotary movement to release the chasers from the camming means and the work, said camming means comprising a cam ring-having a plurality of forwardly ro'ectin trian ularlv formed cams.

16. A chaser for a die having its outermost or top surface curved or tapered circumferentially and straight axially of the body and adapted to be engaged by a cam, and a broad guide plate secured to the back of said chaser and having its top surface lower than the cam formed surface of the chaser and said back plate having a rearwardly extending pin.

17. A cam ring for a threading die having at one edge a plurality of independent forwardly projecting triangularly formed cam surfaces, one side of each effective for adjusting a chaser to cut a right hand thread and the other side of each effective for adjusting a chaser to cut a left hand thread and having a recess in its opposite edge.

18, A self opening threading die comprising a shank, a shell and chaser carrying body floatingly connected with said shank, said body movable axially and rotatable after the forward movement of the die has stopped thereby to release the chasers from the work, radially movable chasers carried by said body, each having its outermost or top surface curved or tapered circumferentially and straight axially of the body, an adjustable but normally non-movable camming means carried by the shell and cooperating with-the chasers, and drawback means for returning the body to its normal position on rotating said body in the reverse direction.

19. A self opening threading die comprising a shank, a shell and chaser carrying body floatingly connected with said shank, said body movable axially and rotatable after the forward movement of the die has stopped thereby to release the chasers from the work, radially movable chasers carried by said body, each having its outermost or top surface curved or tapered circumferentially and straight axially of the body, an adjustable but normally non-movable camming means carried by the shell and cooperating with the chasers, and drawback means for returning the body to its normal position on rotating said body in the reverse direction, said camming means comprising a cam ring having a plurality of forwardly projecting independent triangularly formed cams, one side of each effective for adjusting achaser to cut a right hand thread and the other side of each effec tive for adjusting a chaser to cut a left hand thread.

20. A self opening threading die comprising a shank, a shell and chaser carrying body resiliently and floatingly connected with said shank, said body movable axially and rotatable after the forward movement of the die has stopped thereby to release the chasers from the work, radially movable chasers carried by said body, each having its outermost or top surface curved or tapered circumferentially and straight axially of the body, an adjustable but normally non-movable camming means carried by the shell and cooperating with the chasers, and drawback means for returning the body to its normal position on rotating said body in the reverse direction.

21. A self opening threading die comprising a shank, a shell resiliently and floatingly connected with said shank and having a bore and a recess forwardly thereof. a die body having a bored shank projecting into the bore of said shell, the body thereof extending into the recess of said shell, said shell being resiliently connected with said body, said body having a plurality of radial chaser-receiving slots, chasers located in said slots and each having a circumferentially curved or tapered cam surface, a cam ring located in said shell around the shank of said body. and having a plurality of triangular formed cam surfaces cooperating with the cam surfaces of said chasers, driving pins carried by said body, a driving plate secured to said shell and having openings for the reception of said driving pins, said plate having a recess in which said openings are. located, the side Walls of said recesses forming stops for limiting the rotary movement of said body independently of the shell, the resilient connection between the shell and body forming a means for drawing the body into the shell and the pins into theopenings of the driving plate, the organization being such that the body and its chasers have an axial movement forwardly and a rotary movement independently of the shell, the axial movement be ing efiective without releasing the cam ring from the chasers but effective to disconnect the driving pins from the driving plate thereby to permit the rotary movement of the body and chasers independently of the shell to release the chasers from the cam ring and the Work after the latter has been completely threaded.

Signed at Cleveland, county of Cuyahoga and7State of Ohio, this 26th day of October, 191

OSCAR A. SMITH.

E- MAS-PERSON- 

